How to label variables

Labeling the variables in a dataset is one of the most basic and fundamental data management tasks. Sometimes, the variable names are clear and useful, but we would like to add a label that will be used in tables and graphs. Let's open and describe an example dataset from the Stata website and we'll show you how.

. use https://www.stata.com/users/youtube/rawdata.dta, clear

. describe

Contains data from https://www.stata.com/users/youtube/rawdata.dta
 Observations:         1,268                  Fictitious data based on the
                                                National Health and Nutrition
                                                Examination Survey
    Variables:            10                  6 Jul 2016 11:17
                                              (_dta has notes)

 
Variable      Storage   Display    Value
    name         type    format    label      Variable label
 
id              str6    %9s                   Identification Number
age             byte    %9.0g                 
sex             byte    %9.0g                 Sex
race            str5    %9s                   Race
height          float   %9.0g                 height (cm)
weight          float   %9.0g                 weight (kg)
sbp             int     %9.0g                 Systolic blood pressure (mm/Hg)
dbp             int     %9.0g                 Diastolic blood pressure (mm/Hg)
chol            str3    %9s                   serum cholesterol (mg/dL)
dob             str18   %18s                  
 
Sorted by: id

The column "Variable label" shows labels for all the variables except age and dob. Most textbooks will advise you to include the units of measurement in a variable label, and age is measured in years. Let's add a label to the variable age.

. label var age "Age (years)"

The variable dob contains the date of birth for each observation. Let's label it too.

. label var dob "Date of Birth"

Let's describe our data again to verify that we have labeled the variables correctly.

. describe

Contains data from https://www.stata.com/users/youtube/rawdata.dta
 Observations:         1,268                  Fictitious data based on the
                                                National Health and Nutrition
                                                Examination Survey
    Variables:            10                  6 Jul 2016 11:17
                                              (_dta has notes)

 
Variable      Storage   Display    Value
    name         type    format    label      Variable label
 
id              str6    %9s                   Identification Number
age             byte    %9.0g                 Age (years)
sex             byte    %9.0g                 Sex
race            str5    %9s                   Race
height          float   %9.0g                 height (cm)
weight          float   %9.0g                 weight (kg)
sbp             int     %9.0g                 Systolic blood pressure (mm/Hg)
dbp             int     %9.0g                 Diastolic blood pressure (mm/Hg)
chol            str3    %9s                   serum cholesterol (mg/dL)
dob             str18   %18s                  Date of Birth
 
Sorted by: id
     Note: Dataset has changed since last saved.

Now we can save our dataset.

. save mydata
file mydata.dta saved

You can watch a demonstration of these commands by clicking on the link to the YouTube video below. You can read more about these commands by clicking on the links to the Stata manual entries below.

See it in action

Watch Data management: How to label variables.